Honing head with oblique abrasive elements and method of making the same



July 2, 1957 G. R. ATKINSON r 2,797,535

HONING HEAD WITH OBLIQUE ABRASIVE ELEMENTS AND v METHOD OF MAKING THE SAME Filed Feb. 8, 195

II M I? I INVENTOR.

Geojrge Reagh fl/k/nson ATTORNEYS HONING HEAD WITH OBLIQUE ABRASIVE ELEMENTS AND METHOD OF MAKING THE S George R. Atkinson, (twosso, Mich, assignor to Mid-West Abrasive Company, Owosso, Mich., a corporation of Delaware Application February 8, 1954, Serial No. 408,669 13 Claims. (Cl.,51184.1)

This invention relates generally. to honing heads and to an improved abrasive element and method of making the same.

It is an object of this invention to provide a honing head comprising a cylindrical shell having elongated abrasive members spaced from each other circumferentially of the shell and extending obliquely relative to the shell axis in a manner such that adjacent abrasive mem bers overlap one another axially of the shell to provide in efiect a continuous abrasive bearing surface around the shell. Thus, accurate centering of thehoning head Within the bore being honed is not only maintained throughout the honing operation but, in addition, uniform pressure of the abrasive members against the working surface of the bore is assured and uniform wear of the abrasive members results.

It is another object of this invention to provide an abrasive element with a contour corresponding to an oblique segment of a hollow cylinder having the radii of the inner and outer surfaces respectively equal to the radii of the inner and outer surfaces of the shell.

It is a further object of this invention to provide the shell of the honing head with slots extending obliquely with respect to the axis of the shell at an angle which substantially corresponds to the angle of the oblique segment of the hollow cylinder aforesaid so that abrasive elements of the type set forth in the preceding paragraph may be readily inserted in the slots.

It is still another object of this invention to provide a relatively simple and inexpensive method of making abrasive members of the foregoing type. In accordance with this invention the specified abrasive material is formed into an elongated section of a hollow cylinder having substantially the same inside and outside diameters as the inside and outside diameters, respectively, of the honing head shell. The elongated section of abrasive material is out along lines which extend obliquely with respect to the section of abrasive material at approximately the same angle as the slots in the shell of the honing head, and which are spaced from one another lengthwise of the section. The resulting segment of abrasive material provides an abrasive element which may be readily inserted in the slots of the shell.

It is a still further object of this invention to reinforce the abrasive member with a metal backing strip comprising an oblique segment of a hollow cylinder having an outside diameter approximating the inside diameter of the hollow cylinder noted in the preceding paragraph. In order that the backing strip will fit the inner surface of the abrasive member without the necessity of resorting to complicated forming operations, the strip is fashioned by the cutting of a metal section of the hollow cylinder aforesaid along lines extending obliquely relative to the section at substantially the same angle as the lines .along which the abrasive section is cut to produce the abrasive member. Thus, the contour of the backing strip will correspond to the contour of the abrasive member and may 2,797,535 Patented July 2, 1957 be cemented or otherwise secured to the inner face of the abrasive member.

The foregoing as Well as other objects will be made more apparent as this description proceeds especially when considered in connection with the accompanying drawing, wherein:

Figure l is a semi-diagrammatic side elevational view of a shell for a honing head;

Figure 2 is a cross sectional view taken substantially on the plane indicated by the line 22 of Figure 1;

Figure 3 is a plan view of a cylindrical section of abrasive material from which the abrading elements shown in Figure 1 are formed;

Figure 4 is a top plan view of the abrading element;

Figure 5 is a cross sectional view taken on the line 5-5 of Figure 3; and

Figure 6 is a cross sectional view through a cylindrical section from which the backing for the abrading element is formed.

In Figures 1 and 2 of the drawing, the numeral 10 designates a cylindrical metal shell having slots 11 spaced from each other 'cii'cumferentially of the shell and extending obliquely'with respect to the axis of the shell. The slots 11 extend through the shell 19 and respectively receive an abrading element 12. The abrading elements 12 each comprise an elongated relatively narrow member 13 formed of a suitable abrasive material, and a backing 14 preferably formed of metal. The backing 14 is cemented or otherwise permanently secured to the inner surface of the abrasive member 13 and serves as a reinforcement for this member.

In practice, the slots 11 extend through the shell 10 and the abrading elements 12 are respectively supported in the slots for movement inwardly and outwardly relative to the shell to vary the effective diameter of the shell. The-means for supporting .and adjusting the abrading elements 12 with respect to the shell 10 form no part of the present invention, and hence such means are not shown herein. In any case the slots 11 and abrading elements 12 are so arranged with respect to the shell 10 that adjacent abrading elements 12 overlie one another axially of the shell 10. The overlying relationship of adjacent abrading elements 12 provides an abrasive bearing surface which extends completely around the shell and thereby assures accurate centering of the shell within a bore being honed by the abrading elements 12. Moreover, since the abrading elements 12 extend obliquely with respect to the shell 10, these elements have in effect a shearing action which greatly increases the effectiveness of the honing operation. In addition, the above relationship of the abrading elements 12 and shell 10 has the eifect of obtaining more uniform pressure of the abrading elements with the surface of the Work being honed. This feature is advantageous in that it enables honing a surface to an accurate cylindrical contour and at the same time assures uniform wear of the abrading elements.

The abrasive member 13 of the abrading element 12 comprises an oblique segment of a hollow cylinder. In accordance with this invention, the abrasive member 13 is formed from an elongated section 15 of a hollow cylinder and the section 15 is composed of the specified abrasive material. The radius R of the outer surface of the section 15 approximates the radius of the outer surface of the shell 10 and the radius R of the inner surface of the section 15 is substantially equal to the radius of the inner surface of the shell 10. The cylindrical section 15 of abrasive material is out along parallel lines 16 .(Fig. 3) which extend oblique with respect to the cylindrical section 15 from one side edge of this section to the opposite side edge of the latter. In the 3 present instance the lines 16 are inclined at an angle of about 45 with respect to a plane perpendicular to the cylindrical section 15 and are spaced from one another lengthwise of the section '15 a distance correspbnding to the specified thickness of the abrasive member 13;

As a result of the cutting of the cylindrical section 15 along thelines 16, an elongated abrasive member is provided which is in the form of an oblique segment of a hollow cylinder corresponding to the shell 10. The extremities of the abrasive member are then trimmed as indicated in Figure 4 of the drawing to provide the abrasive member 13. After the reinforcing backing strip 14 is cemented or otherwise secured to the inner surface of the abrasive member 13 to form the a'bradin'g element 12, the latter is insertable into one of the slots 11 in the shell 10. elements'lz into the respective slotsll in the shell 10,

the slots 11 are formed in the shell so that they extend obliquely relative to the shell at the same angle as the lines 16 along which the abrasive cylindrical'section is cut to form the abrasive member 13. It will of course be understood that the slots 11 are sufficiently wider and longer than the abrading elements 12to enable the ready insertion of the latter in the respective slots.

The backing be fashioned in any suitable manner to conform to the inner surface of the abrasivemember 13. However, it is preferred to provide a backing strip 14 which also comprises a segment of a hollow cylinder so that the backing strip may be readily applied to the inner surface of the abrasive member the same angle as the lines 16. In addition, the radius of the outer surface of the section 17 is substantially the same as the radius R abrasive section 15 with the result that the strip cut from the section 17 corresponds in contour to the inner In order to provide for fitting the abrading' strip 14 for the abrading element 12 may 13 without theforming or fashioning of the strip to the contour of the inner surface of the of the inner surface of the a backing strip to the inner surface of said member.

- which the abrasive The lines along which the section 17 is surface of the abrasive member 13and may be readily secured thereto to form the backiug14.

When the abrading elements 12 are adjusted outwardly beyond the position corresponding to their cylindricaltrace of origin in the blank 15, the operative su'rfacesof the elements will nolonger be entirely on a new imaginary cylindrical surface. Accordingly, some degree of excessive wear will occur over certain portions of theop erative surfaces of the'elements until such operative surfaces are ground away to a point Where they will be entirely on a'newimaginarycylindrical surface.

-It follows from the foregoing that the" present invention renders it practical to provide a honing head with abrading elements which extend obliquelywith respect to the shell or casing of the head in a manner such that adjacent abrading elements actually overlie one another axially of the shell. As a result of the method previously described for forming the abrading'eleme'nts, it is possible to produce ah'oning head' of the type set forth at a cost competitive with conventional honing heads wherein the abrading elements extend parallel to the axis of rotation of the head. I

WhatIclaim asmy inventionisj n A l. The method of making an abrasive member which comprises forming from 'an'abrasive material a section of a hollow cylinder having the radius of the'inner wall sufficiently smaller than the radius of theouter wall to provide the section with a wall thickness approximating 4. T he m ethod defined in claim 3 wherein the backing strip is fashioned by the steps of forming from the backing material an elongated section of a hollow cylinder having the radius of the outer surface approximating the radius of the inner surface of the abrasive section, cutting the section of backing material along lines spaced from one another lengthwise of the backing material section and extending obliquely of the backing material section at an angle approximating the angle of the lines along section is cut to form the abrasive segment; 7

A, j. The method of makingan' abrasive member which comprises forming from an abrasive material a section of a hollow cylinder having the radius of the inner wall su fii ciently smaller than the radius of the outer wall to provideth'e section'witha wall thickness approximating the thickness of the'abrasive member, cutting the section along lines disposedin planes substantially parallel to each other extending obliquely relative to the cylindrical sectionand apaced apart a distanceapproximating the width of the abrasive member to provide an elongated abrasive segment, andtrimming said segment along lines extending transversely of said first-mentioned lines in spaced relation longitudinally of said first-mentioned hnes to provide the abrasive member of specified length and width.

6. The method defined in claim 5 including the steps of providing a backing strip for said abrasive member by forming from the backing material a section of a hollow cylinder having the radius of the outer surface approximating the radius of the inner surface of the abrasive section, cutting the section of backing material along lines disposed in planes substantially parallel to each other extending obliquely of the backing material section at an angle approximating the angle of the lines along which the abrasive section is cut and spaced apart a distance approximating the width of said abrasive member, and securin'g said backing strip to the inner surface of said abrasive member to reinforce the latter.

7. A honing head comprising a cylindrical shell having a plurality of elongated slots spaced from each other circumferentiallyof said shell, the opposite longitudinal sides ofsaid slots being disposed in spacedparallel planes extending obliquely relative to the axis of said shell, and

elongated abrasive members respectively supported in said slots, the opposite longitudinal sides of said members extending'parallel tothe opposite sides of said slots.

8. A honing head as defined in claim 7 in which said members each have opposite ends and each member, be cause of its obliquearrangement relative to said shell, has one of its ends spaced circumferentially in one direction relative to said shell from the other of its ends, the circumferential spacing between said members and the length thereof being such that said one end of each member extends circumferentially beyond the said other end of an adjacent member was to provide in effect a continuous abrasive bearing surface extending about the circumference of said shell. I g

9. A honing head as defined in claim 8 in which the radii of the inner and outer surfaces of said members respectively approximate the radii of the inner and outer surfaces of said shell.

10. A honing head as defined in claim 9 having an elongated backing strip for each abrasive member, said strips each comprising an elongated segment of a cylinder, the outer surface of each segment conforming in shape to the inner surface of the associated members and being secured thereto, and the opposite longitudinal sides of each segment extending parallel to the opposite longitudinal sides of the associated member.

11. An abrading element for honing tools comprising an elongated oblique segment of a hollow cylinder having a predetermined angle to a plane perpendicular to the axis of the hollow cylinder, the opposite longitudinal sides of said segment being disposed in spaced parallel planes and said segment being composed of abrasive material, and a backing strip comprising an elongated oblique segment of a hollow cylinder having an angle to a plane perpendicular to the axis of the second-mentioned hollow cylinder equal to the aforesaid predetermined angle, the outer surface of said strip conforming in shape to the inner surface of said abrasive segment and being secured thereto, and the opposite longitudinal sides of said backing strip extending flush with the opposite longitudinal sides of said elongated segment.

12. In a honing assembly, a honing head, and a plurality of abrading elements carried by said head in circumferentially spaced relation thereabout, said elements being composed of abrasive material and comprising oblique elongated segments of a hollow cylinder having parallel opposite longitudinal sides extending at a predetermined angle to a plane perpendicular to the axis of the hollow cylinder,

the hollow cylinder having concentric radially inner and outer cylindrical surfaces, said elements being obliquely arranged on said head at the aforesaid predetermined angle with respect to a plane perpendicular to the axis of said head and in circumferentially spaced relation to each other about said head.

13. The assembly defined in claim 12 in which said elements each have opposite ends and each element, because of its oblique arrangement on said head, has one of its ends spaced circumferentially in one direction relative to said head from the other of its ends, the circumferential spacing between said elements and the length thereof being such that said one end of each element extends circumferentially beyond the said other end of an adjacent element so as to provide in effect a continuous abrasive bearing surface entirely about the circumference of said head.

References Cited in the file of this patent UNITED STATES PATENTS 1,575,267 Houldsworth Mar. 2, 1926 2,038,295 Kaminsky Apr. 21, 1936 2,338,963 Palotce Jan. 11, 1944 2,729,919 Krafft Jan. 10, 1956 FOREIGN PATENTS 296,027 Great Britain July 18, 1929 758,139 Germany Aug. 2, 1951 

